.text
.globl in_byte
.type in_byte, @function
in_byte:
    movl 4(%esp), %edx
    inb %dx, %al
    ret

.globl out_byte
.type out_byte, @function
out_byte:
    movl 4(%esp), %edx
    movl 8(%esp), %eax
    outb %al, %dx
    ret